This invention relates to an agricultural implement and in particular to an improved disc-type opener and seeder useful in direct seeding in low or zero tillage operations.
In recent years there has been an increased demand for more precise seed placement, reduced soil disturbance and displacement, reduced soil moisture loss incurred with soil tillage, reduced fuel consumption, reduced weed seed incorporation (resulting in reduced chemical usage) and increased efficiency, productivity and versatility for on-site farm equipment.
The above demands are due to a shift from conventional tillage practices to the new "zero tillage" environmentally sustainable practices of agriculture. To accomplish the goal of zero tillage a new practice termed "direct seeding" has been introduced into agriculture. The only seeding or planting tool capable of achieving "direct seeding" and "zero tillage" is a disc type opener.
There is also a need to address the matter of fuel conservation, by providing the agricultural industry with a seeding or planting tool that can meet the demands of the "zero till" minded farmers: accurate seed placement, (including positive individual disc opener depth control) zero tillage, moisture conservation, reduced weed seed incorporation, and a reduction in herbicide use, all meeting the demand for a reduction in fuel consumption in the agricultural industry. As seeding or planting is the first operation in the production of grain, providing a seeding or planting tool that requires no pre-seeding tillage, and considerably less horse power than the chisel plow type of air seeders, a large number of agricultural producers will switch to "zero tillage" and "soil conservation".
When "direct seeding" into untilled soil, accurate seed placement has proven to be a major problem, the problem being "hairpinning" Hairpinning occurs when straw, trash and/or crop residue becomes embedded in the seed furrow when the disc of the disc opener does not cut completely through the straw, trash and/or crop residue. This debris ends up in the seed furrow and is distributed from the bottom through to and out the top of the seed furrow. Seed is dispensed by the seed boot on top of this debris, and as the trailing half of the disc opener disc retracts from the seed furrow, the disc drags some of the straw, trash and/or crop residue back out of the seed furrow taking some of the seed up with it and depositing it at various levels and actually tossing some of the seed right up on top of the soil surface, resulting in erratic seed placement and very poor seed germination. Hair pinning also causes moisture loss due to the wick action of the exposed portions of the straw, trash and/or crop residue in the seed furrow.